Tones 聲調/声调 shēng diào
中文是一种声调语言。发音相同但声调不同的单词通常具有不同的含义。基本上，汉语口语有四个主要声调和一个轻（中性）声调。 Chinese is a tonal language. Words with the same pronunciation but different tones usually have the different meanings. Basically, there are four primary tones and a light (neutral) tone in the Spoken Chinese.
Tone Scale 聲調音階/声调音阶 shēng diào yīn jiē
By examining the Chinese Tone Scale invented by Dr. Zhào Yuánrèn (赵元任博士), we can generate the following table on Tone Comparison. Dr. Zhāo depicted Chinese tones in a five-point-scale chart. The first tone, staying in the highest scale 5 (scale as '55')，is flat and steady. The second tone rises upward from scale 3 to 5 (scale as '35'). The third tone is slightly downward from scale 2 to 1, and then rises upward to scale 4 (scale as '214'). The forth tone has a sharp drop from scale 5 to 1 (scale as '51'). The tone mark of these four primary tones are identical to their tone scale. However, no tone mark is placed on a neutral(light) tone from the Hanyu Pinyin system. The syllable on the neutral tone is unstressed and is pronounced in a "weak" tone. Generally speaking, the characteristics of a neutral tone are light and short, with the absence of a tone mark.
Where to Place A Tone mark?
Tone mark is placed above the main vowels such as on the top of the single vowels "a", "o", "e"，“i”，“u”,or "ǚ"; or on the first of the compound (double) vowels such as "ai", "ei", "ao", or "ou". Please note that tone mark is not placed on the top of the conjunction vowel, i-, u-, or ǚ- . Instead, it is placed on the main vowel following after the conjunction vowel, i-, u-, or ǚ- . One exception is when there is no any vowel(s) after a conjunction vowel. Then, tone mark is placed above either on "i", "u", or "ǚ". Under this condition "i", "u", or "ǚ" is perceived as the main vowels. The dot over the vowel "i" should be dropped if there is a tone mark placed above it.
Scale Change on third-tone words
A third-tone syllable which appears alone or at the end of a sentence is usually pronounced with its full scale (214). However, a third-tone word is not pronounced with its full scale (214) when there is any word placed after it. Under this condition, only the front half scale (21 scale) is pronounced. For the concern of the time efficiency, we can pronounce all third-tone words with only the half scale (21).
Several tone changes have to be made when the third-tone words are pronounced
1. Third-tone Sandhis (三生變調/三声变调）
2. "一“ (one) and "不” (not)
- 'Third tone + third tone'=> pronounced as 'second tone + third tone'.
- When three third tones appear in series with no pauses in between, the first two are pronounced in the second tone.
2. "一“ (one) and "不” (not)
- When the character '一' represents the number '1', it is pronounced in the first tone 'yī'.
- When "不“ is by itself, it is pronounced in the forth tone.
- When "一” or "不“ followed after a first (1st), second (2nd) or a third (3rd) tone, it is pronounced in fourth tone.
- When "一” or "不“ followed after a fourth tone, it is pronounced in second tone.